1. Field of the Invention
The present invention relates to a data recording device for a camera and a camera with a film counter which is capable of mount a long film back.
2. Related Background Art
The data recording device (to be referred to as "a data back" hereinafter in this specification) can select a plurality of data recording modes. For instance, in order to select one of the fundamental data "year-month-day", "day-hour-minute" and "hour-minute-second", upon depression of the operating botton, the selected fundamental modes is displayed by a LCD for the exterior displaying and upon operating a shutter, the data data displayed is recorded on the surface of the film. In addition to the data recording function described above, the data back has various functions. That is, the data back has various control modes corresponding the above-described function and a user may freely select a desired control mode. In order to accomplish a special function, it is needed to record the special function or a control mode corresponding thereto. Among such functions, the so-called bracketing exposure control to perform blacketing photography is well known in the art.
According to the conventional techniques described above, the data recording function, the control function such as bracketing and a function of recording a selected fundamental data are only incorporated with a camera body and operating members and the conventional cameras have no highly advanced function for selecting the data concerning the control function such as bracketing and recording it on the surface of the film.
There have been proposed various types of cameras capable of recording on the surface of a film in terms of numerals the data of an exposure.
In general, the data recording device is incorporated with the camera back and has a recording means consisting of a plurality of light-emitting diodes (LED) arranged to be turned on to indicate numerals and a display means such as a liquid crystal display (LCD) for displaying the numerals to be recorded. In the case of recording, LEDs are turned on in synchronism with the exposure operation so as to record the selected data on the film and the contents of the data can be confirmed prior to the exposure. However, in the case of such conventional data recording device, the data to be recorded on the film must coincide with the data displayed by the displaying means so that the number of digits of the data to be recorded on the film is coincident with the number of digits of the numeral displayed by the display means.
Recently the demand for increasing the functions carried out by the data recording device is increasing. That is, in addition to a calendar data represented by a year, a month and a day, it is demanded to record on the film and display various data such as the number of exposed frames of a film, an exposure coefficient and the like. Furthermore, a function such as an interval mode or the like different from the fundamental recording function is desired to be incorporated in the camera. In order to satisfy the above-described demands, it is needed not only to increase the number of digits of the recording means, but also to enlarge a liquid crystal display so that various data may be displayed. However, the recording device incorporating the above-described functions becomes large in size and only a limited space is available in the camera back, it is difficult to recording device in the camera back. Even when the recording device is incorporated in the camera back, it is impossible to satisfy all the functions demanded described above.
There have been devised and demonstrated various types of cameras in each of which a film counter for counting the number of exposed frames is incorporated so that every time when one exposure is made, the value of the film counter is incremented by one and is displayed.
However, the length of the film loaded in the camera is limited. Therefore, when it is desired to expose a large number of frames, employed is a method in which a long-film back is loaded on the camera body and a long film cut out from a film roll is set into the long-film back so that hundreds of frames can be continuously exposed.
In the case of the camera loaded with the long film back as described above, the number to be counted by the film counter incorporated in the camera body is limited and so far only a two digit number is displayed. In the case of the display a number of exposure counted by the film counter when a long-film back is mounted on a camera, when the display of the number of exposures of the frames of a long-film back is made by the camera body, the display of the frames of the film counted by, for instance, a mechanical film counter is interrupted at the highest number which the mechanical counter can count. As a result, the display of the number of the exposed frames of the long-film back is in excess of the limited value of the camera body, they do not coincide with each other so that there is a fear that a user erronesouly recognizes the number of exposures made during photographing. Furthermore, in the case of a long-film back incorporated with a down counter means displaying the number of frames to be exposed, when the down or decrement counting mode is selected, the display by the camera body does not coincide with the display by the long-film back so that there still remains a fear that the user erroneously recognizes the number of frames to be exposed.